HI Gregg,
Congratulations on your purchase.
I had the same experience as you with my build, with the threat of the new ADRS coming into play I had about 3 months to finish my car to a standard that would pass engineering and registration.
I would check with your engineer, but there are many things you can do without. You will find that a very basic car, without bumpers, windscreen, wipers etc will pass.
The cr community is fairly strong and there will always be someone arround for advice or help, I know that there is an underbody exhaust system that a few guys have used for rego.
As you are not looking at ppainting straight away, ask Ian if he will used coloured Gel Coat when making the body, they can look quite good at a few paces. Craigs brother John, has done his this way and the car looks great.
I understand that there are few options on motor choices so if you have to build a rebodied comodore thats ok, we all cant have the best....
Good luck, enjoy your build.
Phil